Exactly. Kind of hard to describe this further without presenting a paint-by-numbers primer for badness.

Combine this with the concept that you only need to penetrate a single terminal and you have access to the sterile area of every other domestic air terminal.

The concept of a "sterile area" is an expensive exercise in futility that diverts scarce resources. Adding layers of inane "security" at the passenger entry portals, even if perfectly designed and implemented, does not change the basic flaw.